![]() |
|
The correlation between maternal CRP and plasma cholesterol levels in a subset of mothers (n = 89) for which both values could be obtained from medical records of the same prenatal examination is shown in Figure 2. The percentage of mothers who smoked during pregnancy was much greater in the hypercholesterolemic group than in the normocholesterolemic group (58.6% vs 38.5%), whereas the average number of cigarettes per day per smoker was similar. CRP also correlated significantly with maternal smoking in univariate analysis (R2 = 0.223; P < .0005). When CRP level was used as a dependable parameter in multivariate analysis, both maternal plasma cholesterol level and smoking remained significant (R2 = 0.408; P < .0005; standardized beta values 0.468 and 0.370, respectively).
The FELIC study had indicated a strong correlation of atherosclerosis with age (Figure 3), which must be kept in mind when assessing correlations of maternal factors with non–age-corrected atherosclerosis data, such as the composite measure of atherosclerosis in the arch and abdominal aorta of children. Nevertheless, in addition to factors previously established as significant (ie, the age of the child [R2 = 0.536; P < .0005], the maternal group [R2 = 0.368; P < .0005], and maternal cholesterol level [R2 = 0.343; P < .0005]), maternal CRP level (R2 = 0.173; P < .0005; Figure 4) and maternal smoking (R2 = 0.084; P < .001) showed significant correlation with offspring atherosclerosis in univariate analysis.
Significant parameters (child age, maternal total cholesterol, CRP, and smoking) were then included in a stepwise multiple regression analysis. Note that, in contrast to the FELIC study, we used the single maternal cholesterol value that was measured at the same time as CRP level, instead of the (highly correlated) maternal group, which was defined by the average maternal cholesterol level during multiple prenatal examinations. As shown in the Table, CRP level remained significant in the multiple regression analysis but showed a low beta factor. Smoking was not significant. Although maternal cholesterol level had a higher correlation than CRP level for childhood atherosclerosis, when cholesterol was removed from the multiple regression analysis, the age of the child and maternal CRP level together still predicted 68% of the atherosclerosis (P < .0005).
CommentEvidence from both human studies and experimental models indicates that maternal hypercholesterolemia programs increased susceptibility to atherosclerosis later in life.5, 7, 8, 24, 25, 26, 27 Unfortunately, maternal hypercholesterolemia is not determined routinely during pregnancy in most Western countries, with the notable exception of Italy, where it is part of the standard clinical laboratory tests that are performed during prenatal examinations.28 Although the mechanisms of developmental programming remain largely unknown, they are clearly dependent on oxidative stress, which is raised both by maternal hypercholesterolemia and smoking.3, 5, 6, 7, 10, 29, 30, 31, 32, 33 Oxidative stress affects the expression of many genes that influence recruitment, differentiation, and secretory activity of macrophages and T cells; conversely, increased inflammation promotes oxidative stress. It was tempting therefore to assume that, in the absence of cholesterol data, elevated maternal levels of CRP, which is a marker of inflammation, might be a surrogate indicator of the atherosclerosis risk of children. The present results indeed establish that maternal CRP level that is measured during the late second/early third trimester is elevated in hypercholesterolemic mothers and that it correlates with the extent of atherogenesis in children, both in univariate and multiple regression analysis. However, CRP level was a lesser indicator of atherogenic programming than maternal cholesterol level. A low beta factor of maternal CRP also makes it unlikely that the postulated atherogenic effects of CRP contribute substantially to in utero programming. It is tempting to conclude that CRP level merely reflects the inflammation that is concomitant with hypercholesterolemia. On the other hand, elevated CRP level is not specific for atherosclerosis, and CRP levels may be confounded by a number of unrelated conditions, such as maternal infections, that may not affect in utero programming. Elevated CRP levels may be a retrospective indicator of postnatal atherogenic risk, where cholesterol levels were not determined, and may prompt cholesterol determination, if detected before or during pregnancy. Maternal smoking, which may induce atherogenic programming in normocholesterolemic animals,30 also correlated with atherosclerosis in children but lost significance when assessed together with maternal hypercholesterolemia. This suggests that oxidative stress–ensuing hypercholesterolemia by itself is more than enough to trigger atherogenic programming in the fetus and that smoking does not further enhance it sufficiently to become an independent predictor. Limitations include the retrospective nature of the FELIC study and the ensuing need to rely on medical records for maternal data during pregnancy. The fact that these data were generated by a number of different clinical laboratories over a 14-year period may have increased variability. The retrospective nature of the study also made it impossible to supplement maternal data during pregnancy by measurements of other lipoproteins, in particular high-density lipoprotein, parameters of oxidative stress (to validate smoking history), and other parameters of inflammation, such as isoprostanes or antibody titers to oxidation-specific epitopes. In particular, uterine infections or general infections and other conditions that raise CRP level may not have been documented in maternal medical records, and their confounding effect may have been underestimated. Furthermore, not all parameters were available in all of the 156 mothers and their children, which reduced the power of the analysis. Finally, the incidence of other maternal conditions that potentially affect oxidative stress, such as maternal diabetes mellitus, was too low to yield reliable data for CRP. Ideally, the association of maternal risk factors with atherogenic programming and coronary heart disease should be assessed in prospective studies, but such studies would have to be very large and span at least 4 decades for cardiovascular outcomes (lesser periods, if surrogate measures of atherosclerosis are considered). References1. 1. Weight in infancy and death from ischaemic heart disease. Lancet. 1989;2:577–580. MEDLINE 2. 2. Fetal nutrition and cardiovascular disease in adult life. Lancet. 1993;341:938–941. Abstract | CrossRef 3. 3. The fetal origins of atherosclerosis: maternal hypercholesterolemia, and cholesterol-lowering or antioxidant treatment during pregnancy influence in utero programming and postnatal susceptibility to atherogenesis. FASEB J. 2002;16:1348–1360. CrossRef 4. 4. Maternal hypercholesterolemia during pregnancy influences the later development of atherosclerosis: clinical and pathogenic implications. Eur Heart J. 2001;22:4–9. CrossRef 5. 5 Fatty streak formation occurs in human fetal aortas and is greatly enhanced by maternal hypercholesterolemia (Intimal accumulation of low density lipoprotein and its oxidation precede monocyte recruitment into early atherosclerotic lesions). J Clin Invest. 1997;100:2680–2690. MEDLINE | CrossRef 6. 6. Maternal hypercholesterolemia enhances atherogenesis in normocholesterolemic rabbits, which is inhibited by antioxidant or lipid-lowering intervention during pregnancy: an experimental model of atherogenic mechanisms in human fetuses. Circ Res. 2000;87:946–952. 7. 7 Maternal hypercholesterolemia and treatment during pregnancy influence the long-term progression of atherosclerosis in offspring of rabbits. Circ Res. 2001;89:991–996. CrossRef 8. 8. Influence of maternal hypercholesterolaemia during pregnancy on progression of early atherosclerotic lesions in childhood: Fate of Early Lesions in Children (FELIC) study. Lancet. 1999;354:1234–1241. Abstract | Full Text | Full-Text PDF (142 KB) | CrossRef 9. 9. Inflammation and cardiovascular disease mechanisms. Am J Clin Nutr. 2006;83:456S–460S. MEDLINE 10. 10 Maternal immunization programs postnatal immune responses and reduces atherosclerosis in offspring. Circ Res. 2006;99:E51–E64. CrossRef 11. 11. Production of C-reactive protein and risk of coronary events in stable and unstable angina: European Concerted Action on Thrombosis and Disabilities Angina Pectoris Study group. Lancet. 1997;349:462–466. Abstract | Full Text | Full-Text PDF (54 KB) | CrossRef 12. 12. C-reactive protein and other markers of inflammation in the prediction of cardiovascular disease in women. N Engl J Med. 2000;342:836–843. MEDLINE | CrossRef 13. 13. Comparison of C-reactive protein and low-density lipoprotein cholesterol levels in the prediction of first cardiovascular events. N Engl J Med. 2002;347:1557–1565. CrossRef 14. 14. C-reactive protein, the metabolic syndrome, and risk of incident cardiovascular events: an 8-year follow-up of 14,719 initially healthy American women. Circulation. 2003;107:391–397. CrossRef 15. 15. Inflammation and atherosclerosis: role of C-reactive protein in risk assessment. Am J Med. 2004;116(suppl):9S–16S. 16. 16. Rapid reduction in C-reactive protein with cerivastatin among 785 patients with primary hypercholesterolemia. Circulation. 2001;103:1191–1193. 17. 17 Antioxidant vitamins C and E improve endothelial function in children with hyperlipidemia: Endothelial Assessment of Risk from Lipids in Youth (EARLY) trial. Circulation. 2003;108:1059–1063. CrossRef 18. 18. Complement activation by C-reactive protein complexes. Ann N Y Acad Sci. 1982;389:235–250. MEDLINE | CrossRef 19. 19. CRP-mediated activation of complement in vivo: assessment by measuring circulating complement–C-reactive protein complexes. J Immunol. 1996;157:473–479. MEDLINE 20. 20 C-reactive protein upregulates complement-inhibitory factors in endothelial cells. Circulation. 2004;109:833–836. CrossRef 21. 21. Direct proinflammatory effect of C-reactive protein on human endothelial cells. Circulation. 2000;102:2165–2168. 22. 22 C-reactive protein upregulates angiotensin type 1 receptors in vascular smooth muscle. Circulation. 2003;107:1783–1790. CrossRef 23. 23 C-reactive protein induces apoptosis in human coronary vascular smooth muscle cells. Circulation. 2004;110:579–587. CrossRef 24. 24. Intracranial arteries of human fetuses are more resistant to hypercholesterolemia-induced fatty streak formation than extracranial arteries. Circulation. 1999;99:2003–2010. 25. 25. Unraveling pleiotropic effects of statins on plaque rupture. Arterioscler Thromb Vasc Biol. 2002;22:1745–1750. CrossRef 26. 26. Impaired EDHF-mediated vasodilatation in adult offspring of rats exposed to a fat-rich diet in pregnancy. J Physiol. 2004;558:943–951. MEDLINE | CrossRef 27. 27 A high-fat diet during rat pregnancy or suckling induces cardiovascular dysfunction in adult offspring. Am J Physiol Regul Integr Comp Physiol. 2005;288:R127–R133. MEDLINE | CrossRef 28. 28. On hypercholesteremia of pregnancy (Contribution to the study of the phenomenon and its current interpretive possibilities). Riv Ital Ginecol. 1967;51:20–50. MEDLINE 29. 29 Maternal hypercholesterolemia during pregnancy promotes early atherogenesis in LDL receptor-deficient mice and alters aortic gene expression determined by microarray. Circulation. 2002;105:1360–1367. CrossRef 30. 30 Cigarette smoking potentiates endothelial dysfunction of forearm resistance vessels in patients with hypercholesterolemia: role of oxidized LDL. Circulation. 1996;93:1346–1353. MEDLINE 31. 31 Prenatal environmental tobacco smoke exposure promotes adult atherogenesis and mitochondrial damage in apolipoprotein E-/- mice fed a chow diet. Circulation. 2004;110:3715–3720. CrossRef 32. 32 Tracing the origins of “fetal origins” of adult diseases: programming by oxidative stress?. Med Hypotheses. 2006;66:38–44. Abstract | Full Text | Full-Text PDF (123 KB) | CrossRef 33. 33. Multiple role of reactive oxygen species in the arterial wall. J Cell Biochem. 2001;82:674–682. MEDLINE | CrossRef a Regional Hospital of Pellegrini and Loreto Crispi Hospital, 2nd School of Medicine, Federico II University, Naples, Italy b Division of Human Pathology, 2nd School of Medicine, Federico II University, Naples, Italy c Division of Obstetrics and Gynecology, Department of General Pathology and Excellence Research Center on Cardiovascular Diseases, 1st School of Medicine, II University of Naples, Naples, Italy d Division of Clinical Pathology, Department of General Pathology and Excellence Research Center on Cardiovascular Diseases, 1st School of Medicine, II University of Naples, Naples, Italy e Department of Medicine, University of California, San Diego, School of Medicine, La Jolla, CA.
Cite this article as: Liguori A, D’Armiento FP, Palagiano A, Palinski W, Napoli C. Maternal C-reactive protein and developmental programming of atherosclerosis. Am J Obstet Gynecol 2008;198:281.e1-281.e5. This study was supported by grants from the Regione Campania and Ministery of University and Research P.R.I.N. 2006 (C. N.) and National Institutes of Health grants HL067792 and HL56989 (C. N. and W.P.). PII: S0002-9378(07)02176-X doi:10.1016/j.ajog.2007.11.027 © 2008 Mosby, Inc. All rights reserved. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||